Skepticism as an Integral Element of Philosophy Through the Years

The area of skepticism is evident in all aspects of philosophy from ancient Greece to modern day philosophy. Skepticism as defined by Merriam-Webster is an attitude of doubt or a disposition to incredulity either in general or toward a particular object. Skepticism questions the possibility of certainty in knowledge. It gives philosophers a framework to work with through dealing with skepticism or completely ignoring it. There are two definition of skepticism, which are split in terms of knowledge. The first is the denial of possibilities of all knowledge, the second is the suspension of judgement due to inadequate evidence. The foundation of epistemological skepticism asks the question “ Is knowledge possible in the first place?”, this comes from the idea that belief in something does not necessarily justify an assertion of knowledge of it.

Skepticism is split into two main train of thought, Academic Skepticism and Pyrrhonian Skepticism. Academic Skepticism holds the idea, knowledge is not possible and we cannot know. It denies knowledge, epistemology, even metaphysics and assumes that knowledge requires that we eliminate all doubt. Academic Skepticism doesn’t doubt truth in itself but the ability of obtaining it. It doubts the reasons themselves whenever reason is used to justify something which can lead to circular arguments. Pyrrhonian Skepticism refuses to take a dogmatic position on any issue including skepticism itself. PS can lead to the Problem of Induction which generalized is whether inductive reasoning leads to knowledge. Skepticism can be divided even further into two more main sections, local skepticism and global skepticism. Local skepticism is pertains to skepticism in particular areas of knowledge such as moral skepticism, skepticism about the external worlds and other minds. Global skepticism is being skeptical about the possibility of any knowledge at all. One other area of skepticism worth mentioning is Cartesian doubt. It is a rationalist approach to knowledge and attempts to show any proposed knowledge claim can be doubted. Its purpose is to use doubt as a way to certain knowledge by finding those things that could not be doubted.

Berkeley’s approach to challenges of skepticism is to reject materialism, propose subjective idealism and prove the existence of God. Berkeley rejected Locke’s distinction between primary and secondary qualities of perception and instead proposed all perception is secondary. Berkeley said “ But it is evident…, that extension, figure, and motion are only ideas existing in the mind and that an idea can be like nothing but another idea….” (p.189). Berkeley says we cannot claim to know a thing as an independently existing material object, but that things are only the ideas we have of them… there are only minds and ideas in the mind.

His second approach is the idea of Subjective idealism which implies that existence is entirely composed of immaterial ideas. Berkeley implies some knowledge is not derived from sense which he called “notions” such as the notion of our own existence or the existence of God. The problem with this is that we can’t just wish things into/out of existence, if existence is just the universe of the ideas and notions in our minds, why can’t we control the universe through thought? Berkeley’s answer to this is the existence of “God”, that is a greater mind compared to human minds which controls this universe of ideas. Berkeley calls this greater mind the “Universal Mind” which orders our perceptions and grants us sense of continuity and allows for the things we perceive to exist distinct from us. Berkeley also claims we do not choose what to perceive, but that there is some “will or spirit” which produces these sensations for us. He continues with the idea that this spirit is constantly perceiving the world so it is constantly outside human perception, which means it doesn’t go away if no one is looking. Berkeley prefers these ideas are initiated by God. He said “Nothing can be more evident to any one that is capable of the least reflection than the existence of God, or a spirit who is intimately present to our minds, producing in them all that variety of ideas or sensations which continually affect us, on whom we have an absolute and entire dependence, in short in whom we live, and move, and have our being.” (Section 149).” Berkeley's answer to the question “Why can’t we perceive God?” is the same reason we can’t perceive each other’s minds, which leads to the conclusion that empirical data being the foundation of knowledge but rejecting the material world as the cause of our sensations and perceptions.

Hume on the other hand also accepted Locke’s empirical method but rejected any knowledge claims outside of a clear experiential basis. Hume argued that the realm of human knowledge was limited to “impressions” and “ideas”, all others were in the realm of things unknowable or simply don’t exist. This implies that Berkeley’s Universal mind could also be a subjective idea that we hold. Instead of our ideas depending on God, Hume argues that we cannot claim to know that it is impossible for God’s existence to depend on our minds. Hume had two thought trains, matters of fact and relations of ideas. Matters of fact are claims that are true but their denials are not inconceivable or contradictory. An example is the claim “I have a fluffy puppy.”, you would have to go out and observe to find it false, it contrasts with Hume’s relations of ideas. Relations of ideas are claims that are true yet their denials are inconceivable/contradictory. A perfect example of this is to try to imagine a three sided triangle, then try to imagine a 2 sided triangle, it is simply impossible. For Hume, all knowledge is limited to simple impressions, simple ideas and the movement back and forth between them. Ideas in first instances are always derived from perception. Hume deals with common sense knowledge claims as a failure because of three ideas which are without justification yet we hold them basic to our understanding of the world. These three ideas are the principle of universal causation, the principle of induction and belief in the external world. The principle of universal causation contains the idea of the assumption that a sequence of events in the future will occur like it always has in the past such as expecting the sun to rise tomorrow morning, this particular example is also called the uniformity of nature. The affirmation that an event happens does not prove it but rather adds to the series of observations. Hume argues we cannot even claim it is “more probable” since it requires the assumption that the past predicts the future. The principle of induction has the following logical arrangement, P) All observed “x” have been “g” where x is fire and g is hot; C) All unobserved “x” are “g”. We are implicitly assuming the uniformity of nature, there is no incoherence in supposing that while some laws of nature held true in the past, it will fail to hold true in the future. There is also no rationally compelling reason to use induction rather then astrology for example, it comes down to our instinct and we cannot help it.